Lighting capability in portable electronic products (such as cellular telephones, digital music players, and personal digital assistants) is an increasingly desirable feature. In addition to the usual liquid crystal display (“LCD”) and keypad backlighting requirements, lighting patterns can be used as visual feedback to the user to convey incoming calls, distinguish Caller ID assignments, and provide phone system status. An emerging area of commercial interest focuses on product differentiation by way of aesthetic lighting enhancements.
One light enhancement approach utilizes digital signal processing of an audio signal to generate a lighting pattern for the light elements in the portable electronic product. In a practical system, this approach requires the audio signal to be ported into the system in the digital domain. The requirements for a dedicated digital signal processor (“DSP”) algorithm to handle audio data make this approach less desirable due to the associated cost, complexity, and physical space limitations (assuming a DSP is not already available in the portable electronic product). Additionally, the requirement for processed audio to be injected in the digital domain makes this approach more restrictive, and system architectures that have auxiliary analog inputs would need additional analog-to-digital conversion capability.
Accordingly, it is desirable to have a simple, low cost system that modulates lighting elements of a portable electronic apparatus using analog audio signals utilized by the portable electronic apparatus. It is also desirable to implement a lighting element modulation system without requiring a DSP. In addition, it is desirable to implement a lighting element modulation system as an integrated device that is easily adaptable to the audio signal flow of common electronic devices such as cellular telephones and digital music players. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.